Shade selection for IPS e.max lithium disilicate crowns on maxillary central incisors: A case report and literature review

Abstract

Shade selection is a critical step in the esthetic rehabilitation of anterior teeth, because the final appearance of an all-ceramic restoration depends on the selected shade, the ceramic material and its thickness, the color of the underlying tooth structure, and the luting cement. This case report and literature review describes the restoration of both maxillary central incisors with IPS e.max lithium disilicate crowns. A 32-year-old woman with a history of dental trauma and repeated composite restorations was dissatisfied with the appearance of her maxillary central incisors, which were lingually inclined, contained extensive composite resin restorations, and showed morphological irregularities. A conservative plan limited to these two teeth was adopted, and IPS e.max crowns were preferred over laminate veneers because of the volume of the existing restorations. After minimal buccal reduction with a knife-edge finish line, shade was selected with the Vita 3D-Master guide and clinical photographs, and the prepared dentin shade (1M2) was also recorded. The first crowns, fabricated in shade 2M1 and cemented with a translucent light-cured resin cement, appeared darker than the neighboring teeth. One week later, they were replaced with higher-value 1M1 crowns, which were cemented with a bleach-shade cement using the same bonding protocol. At the 6-month follow-up, the restorations blended with the neighboring dentition in color, form, and surface texture. The reviewed literature indicates that visual shade selection is subjective and is best combined with instrumental methods; that value is the most important dimension of color perception; and that ceramic thickness, substrate color, and cement shade can cause perceptible color differences in glass-ceramic restorations. Within the limitations of a single case, natural esthetic results can be achieved even when only two anterior teeth are restored, provided that visual and digital methods are combined, the color–material–cement interaction is managed, and clinician and technician communicate closely.